lost. If it is then necessary to gather pump, pipe and other equipment, which during the year has been used in various ways about the place, and assemble all into some kind of a haphazard and temporary installation, the chances are that he gets water on the crop only after it is damaged beyond recovery. He has then spent his time and money, does not get an adequate return, and he says irrigation does not pay. If, on the other hand, the plant has been properly installed, so that it is always ready to run, there is less reason to procrastinate when the crop is in need of water, and when the farmer does make up his mind to irrigate he can proceed without delay. This gives the pumping plant somewhat the same status as an insurance policy-something provided for in advance of the need for it, forgotten until it is needed, but when needed is ready to serve. Under these circumstances the pumping plant becomes efficient, satisfactory, and effective crop insurance. The size, or the capacity, of the plant is also a factor in its success or failure. It might seem, perhaps, that in a region where the rainfall is upward of 20 inches, it would not be necessary to provide as large a water supply for a given number of acres as where the rainfall is less than 10 inches, but ordinarily such is not the case. It would be folly to attempt to save an 80-acre field of corn with a pumping plant capable of irrigating but two acres a day. In general those sizes referred to earlier will be found adequate for most farms. It is always necessary to have a plant large enough to provide a satisfactory irrigating "head," and where the plant is small, the labor cost incident to spreading the water may often equal or exceed the cost of pumping it. FARMER SHOULD HAVE COMPETENT ADVICE. In the foregoing discussion it is assumed that the farmer had competent engineering advice in the examination of his water supply and the design of his pumping plant. Developing the water supply has not been reduced to the engineering science to which the design of the pump, motor or engine has been. An engineer can determine with mathematical accuracy the speed at which a given pump should be run to give the highest efficiency, what its capacity will be at that speed, and how much power it will take to operate it under a given head, but the amount of water a well will yield cannot be computed by any process of mathematics, even when all information obtainable is at hand. This fact makes the installation of a successful irrigation plant much more complicated than is generally supposed. The well system is the heart of the irrigation plant. The success or failure of the entire plant depends upon it. The best grade of machinery, the most careful computations on the size of the pipe, pump and engine, cannot make an irrigation plant successful if the well fails to yield the water expected of it. In most instances it is necessary to buy the machinery before the capacity of the wells has been determined. For efficient operation the pump and power should be properly proportioned to the capacity of the wells. After the machinery has been installed it is then too late to correct errors made by overestimating the water supply. The first step in the determination of the water supply is to put down a test well at the place where it is proposed to locate the irrigation plant. This well should be put entirely through all valuable water-bearing formations, and should, if possible, reach an impervious floor. The diameter of the well is not important. It may be any size which the tools at hand make desirable. The information secured from this test well will show the depth to the water table, the nature of the water-bearing material, whether coarse or fine sand, the thickness of each stratum and the nature of any layers of impervious material which may be encountered. It will furnish information for determining the type of plant best adapted to the conditions, the amount of well casing needed, and the size of the perforations in it. In the hands of experienced men it will also furnish information regarding the probable amount of water the wells will yield. Without the test well the planning of an irrigation plant is a very uncertain proposition. The failure to have a test made before the construction of the plant has been the cause of more unnecessary expense, low efficiency, and general dissatisfaction then any other single element entering into the installation of the plant. Stress is laid on this because of the seeming reluctance of many farmers to have a test made before buying their well casing, pipe and machinery. When it is known that he intends to put in an irrigation plant the farmer is often besieged with pump salesmen, well men who have their own particular type of well casing to sell, and inventors who are certain they have discovered something which will pump "twice the water with half the power." To rid himself of them the farmer often purchases something against his better judgment and without due consideration of its fitness for his peculiar conditions. In most localities where this condition prevails, we find almost as many different types as there are plants in use. Few of them are efficient, many unsatisfactory, and most of them costing more than well designed plants Icould be built for. Since sound engineering principles have been applied to the problem, much has been accomplished towards standardization of types adapted to the requirements of various conditions of lift and water supply. The freak plant has been almost entirely eliminated, and the cost of construction greatly reduced. As an illustration, in the valleys it has become standard practice, where the depth to water is 25 feet or less, to use 16-inch wells spaced 40 feet apart center to center, using as many wells for each plant as will be required to yield the desired amount of water. Sufficient tests have been made of plants of this type, and the yield of such wells studied sufficiently, so that where the log of a well for a prospective pumping plant is available, and the material from the well can be examined enough to classify it as good, medium or poor, the probable yield of the well system, and the pumping head, can be determined, and the pumping plant can then be designed with every assurance that when finished it will do what is expected of it. CHAPTER II. THE PROPOSED ARKANSAS RIVER COMPACT. The controversy over the use of the water of the Arkansas river for irrigation has been referred to from time to time in the biennial reports of the Division of Irrigation. The issues involved were discussed in the 1919-'20 report. Legislation was enacted in Colorado in 1921 and in Kansas in 1923, providing for an interstate commission and the appointment of commissioners. Meetings of the commissioners began soon after the appointment of the Kansas commissioner in June, 1923. After considerable study and deliberation, the commissioners, in November, 1924, brought out the preliminary draft of a proposed compact. This was submitted to interested parties of both states for criticism and suggestions, and in June of the following year a revised draft was made which is printed here as the proposed compact. GENERAL PROVISIONS OF COMPACT. Briefly, the compact provides for a channel reservoir or reservoirs on the Purgatoire river in Colorado to store the surplus waters of that stream for use in Kansas to supplement the amount now received by the Kansas ditches from direct flow. At the outset it was apparent that the commissioners had a very difficult task on their hands. The natural summer flow of the Arkansas river has been overappropriated for years. The use of water under these appropriations, in most instances, had, through long use, ripened into property rights which could not be taken away without the consent of the vested owners. Because of this the commissioners felt that any attempt to merely allocate or apportion among the various users the available summer water could not solve the problem, since like a court decree, where the victorious litigant secures his water at the expense of the defeated one, it would merely transfer the shortage of water from one locality to another. If the commissioners could accomplish no more than that, the compact method of settling the controversy apparently would have little advantage over allowing the pending suits to be carried to a conclusion in the courts. The commissioners felt that such action would not provide a satisfactory solution, but that a more constructive solution would be for the states involved to jointly construct reservoirs to store additional water, and thus minimize the conflict, and so far as possible leave undisturbed the vested rights in the two states. This meant additional storage on the stream, and storage of the type necessary to equalize the flow of the stream over long periods of time. An examination of the records of the flow of the Arkansas river at the Kansas-Colorado state line indicated that, notwithstanding the fact that the Kansas ditches are periodically short of water, and that frequently this shortage be comes so acute that crops suffer serious damage, when the average annual flow is consulted it appears that if properly controlled there would be enough water to meet the needs of the Kansas ditches. It does at least suggest the possibility that reservoir control could do much toward a solution of the problem, and among other things a study was undertaken, directed toward finding whether or not sufficient storage could be found to effect the desired control. While there were two or three small reservoir sites in Kansas, none were channel reservoirs, and none were of the kind necessary to provide the heavy reservoir control required to impound flood waters and equalize the flow of the stream from year to year. In Colorado, the Purgatoire river, the largest tributary of the Arkansas, having its headwaters in the Sangre de Cristo mountains west of Trinidad, and emptying into the Arkansas at Las Animas, about 65 miles west of the interstate line, seemed to offer the most promising solution of the problem. There are four undeveloped channel reservoir sites on that stream in the cañon below Trinidad. Beginning at the upper end of the cañon they are: Mammoth, capacity 178,000 acre-feet; Chauquaqua, capacity 174,000 acre-feet; Purgatoire No. 2, 123,000 acre-feet; I. S., capacity 83,000 acre-feet. It is evident, of course, that the combined storage capacity greatly exceeds the available water on the stream. Information regarding the existence of these sites is of interest, however, in that it shows that additional storage can be built when necessary to offset the accumulation of silt in reservoirs previously constructed. This would be permitted under article II of the proposed compact, which gives Kansas the right to maintain and operate a reservoir, or reservoirs, to a capacity of 120,000 acre-feet. Records of stream-flow on the Purgatoire indicate an average annual flow near the mouth of 98,700 acre-feet for the period 1906 to 1925 inclusive. It appears from a study of these records that with a reservoir of 120,000 acre-feet capacity, nearly 95 per cent of this water can be controlled. In its present uncontrolled condition, the five Kansas canals, which at one time or another were involved in interstate water litigation, obtain from the Arkansas river by direct diversion during the nine months March to November, inclusive, about 58,500 acre-feet, or somewhat less than one acre-foot per acre. If the provisions of the proposed treaty were carried out, these Kansas ditches could obtain from the Purgatoire reservoir, allowing ten per cent for loss in transit, an average of 62,500 acre-feet annually, or about an acre-foot per acre of land. Considering the value of stored water from the standpoint of the irrigation farmer, the proposed reservoir project is remarkably cheap. The project involves only the construction of a dam, and since the lands, rights of way and easements necessary for the construction and operation of the reservoir would be furnished by Colorado, the actual cost of the dam alone would be borne by the Kansas ditches. Surveys made at the dam site of Purgatoire No. 2 reservoir show that an earth-fill dam would require 960,000 cubic yards of material. It has been estimated that the dam could be built for about $720,000, which would be but a little over ten dollars an acre for the land under the Kansas ditches which would benefit from its construction. In the beginning the Kansas commissioner enjoyed the coöperation of the interested parties in Kansas. Later a lack of interest was shown, and when in addition to this lack of interest, the plaintiffs in the present interstate suits expressed distrust in the project, the matter was laid aside until sufficient interest in it is shown to justify further work on it. The proposed Arkansas river compact follows: |